The present invention generally relates to assembly jigs and, more particularly, to a novel and unique method and jig used in the assembling of reinforcing bar pier cages typically used in the construction art to reinforce concrete piers, caissons, pilasters and the like. Moreover, the present invention provides a jig utilizing a mobile and pivotable framework.
Traditionally, the assembling of reinforcing bar (abbreviated "rebar" in the art) grids and pier cages from individual lengths of rebar is time consuming, physically demanding work. For assembling a rebar pier cage, at least two sawhorses are used upon which the pier cage is assembled. A typical rebar pier cage is of rectangular configuration and comprises at least four elongated rebars and a plurality of longitudinally spaced, rectangular or square formed rebars (termed "stirrups" in the art). Thus, four elongated, steel rebars which comprise the vertical supports of the pier cage are laid across the sawhorses parallel to each other and sequentially marked with chalk at the positions where the stirrups are to be positioned. The stirrups are placed in encircling relation around two of the vertical rods which are positioned at and abut adjacent corners of the stirrups. The stirrups are secured to the elongated rebars with appropriate tie clasps with each stirrup lying in equally longitudinally spaced, parallel planes which are perpendicular to the axes of the elongated rebars. The remaining two elongated rebars are then extended through each of the stirrups in longitudinal succession and positioned at and abut the remaining two corners thereof. The stirrups are then secured with tie clasps to the remaining two rebars, thereby completing the rebar pier cage which is substantially rectangular in shape.
The physical and temporal demands of assembling a rebar pier cage vary directly with the overall dimensions of the cage, i.e., the larger the cage, the longer it takes to complete, and the heavier and bulkier it is to move about. No other methods of assembling rebar piers, which ease both the physical and temporal demands on a worker, are known to the applicant.
It is therefore a principal object of the present invention to provide a method and apparatus for assembling reinforcing bar pier cages, and the like, which substantially reduces the physical and temporal demands of an assembly worker over previously known assembly methods and apparatus.
It is an additional object of the present invention to provide an assembly jig for rebar pier cages which is mobile and easy to use.
It is a further object of the present invention to provide an assembly jig for rebar pier cages which substantially eliminates the need for the completed pier cage to be manually lifted from the horizontal assembly position to a vertical standing position.
It is yet another object of the present invention to provide an assembly jig for rebar pier cages which facilitates the layout and tying of pier cages by providing an assembly work area which is substantially between the waist and chest levels of the assembly worker(s).
It is an additional object of the present invention to provide an assembly jig for rebar pier cages capable of constructing rebar pier cages of varying shapes and sizes.
It is a further object of the present invention to provide an assembly jig for rebar pier cages which substantially reduces the labor cost of assembling pier cages over traditional methods.
Other objects will in part be obvious and in part appear hereinafter.